No first field of table index for ACDOCA

Hi all,

I am running the Code Inspector on a slow performing piece of standard code. I receive message:

"S/4HANA - large table ACDOCA: WHERE condition does not contain any fields of an HDB table index"

Answers to previous question doesn't seem to apply here:
https://archive.sap.com/discussions/thread/3290248

Here's the statement:

SELECT (lt_columns_secure) ##DB_FEATURE_MODE[TABLE_LEN_MAX1]
	FROM acdoca 
	INTO CORRESPONDING FIELDS OF TABLE lt_acdoca_bi   
                                    FOR ALL ENTRIES IN lt_acdoca_pckg
                                    WHERE rldnr  = lt_acdoca_pckg-rldnr
                                    AND   rbukrs = lt_acdoca_pckg-rbukrs
                                    AND   gjahr  = lt_acdoca_pckg-gjahr
                                    AND   belnr  = lt_acdoca_pckg-belnr
                                    AND   docln  = lt_acdoca_pckg-docln.

Here are the database table keys:

RCLNT
RLDNR
RBUKRS
GJAHR
BELNR
DOCLN

The first field RCLNT is the Client (Data Element = MANDT). I would expect that this is not needed, right?

What do you think?